Process of dyeing cellulose-acetate silk



Patented June 12, 1928.

UNITED STATES PATENT OFFICE.

GUSTAV BEDDELIEN AND GEORG MATZDORF, OF LEIIPZIG, GERMANY, ASSIGNORS, BY MESNE ASSIGNMENTS, 10 GRASSELLI DYESTUFF CORPORATION, OF NEW YORK,

N. Y., .A. CORPORATION or DELAWARE.

PROCESS OF DYEING CELLULOSE-ACETATE SILK.

No Drawing. Application filed July 15, 1927, Serial No. 206,123, and in Germany July 24, 1926.

This invention relates to processes of dye-' ing artificial silk, and particularly to dyeing artificialsilk containing cellulose acetate.

We have found that artificial silk contain- 5 ing cellulose acetate may be dyed by treating the same with a suspension of an azo-dyestuff of the general formula alkyl-OH R-N=NRN alkylOH wherein R and R represent aromatic radicles of the benzene series.

Dyestuffs of this kind are obtained by coupling any aromatic diazo compound with an N -dihydroxydialkyl-derivative of an aromatic amine. y

The dyeings are remarkable for their clearness and fastness to washing, water and 0 light. They also have good level dyeing properties, producing dyeings of uniform depth and strength of coloring, which have not hitherto been observed in the known suspension dyestuffs for acetate silk.

For example, 100 parts by weight of acetate silk are dyed for 30-45 minutes at 6070 C. with addition of soap in a suspension of 7.5 parts of l-nitraniline-azo-dihydroxydiethylaniline in water and then washed for a short time. There is thus obtained a clear yellowish red.

dihydroxydietllylaniline wherein R and R represent aromatic radicles of the benzene series.

2. Process of dyeing cellulose acetate silk which comprises treating the same with an aqueous suspension of the azo dyestuff having most probably the general formula CHzCH:OH

-- \CH:CH2OH In testimonywhereof, we affix our signatures.

DR. GUSTAV REDDELIEN. GEORG MATZDORF. 

